Testing of the London Bus DMR Network has started. From where I live I am receiving DMR in the clear from them on 139.66875MHz, this has been receivable for the last 3 weeks or so. Eventualy the system will be encrypted.
Their current MPT1327 and the new DMR Tier III system use the frequencies between 139.500 and 140.500MHz..

Does this testing and upcoming change explain why I can now hear drivers on the 1to1 calls? In the past I could only hear the controller during 1to1 calls but on on group calls I could hear all drivers on the route. Now I can hear both sides all the time.

From Slough I can only pick up the one frequency, but a listener East of London has reported three live DMR frequencies from his location..
Might be worth a search of their band looking for the DMR beacon..

indeed picking up two very active freqs from the old 2217 (8A9) site. have started to compile a list of the talkgroups but will be a waste of time once it goes encripted, radiosification if you pm me i can supply you the actual freqs and colourcodes/timeslots

Lots of bad feedback on my company intranet forum about the new system.

Problems reported from controllers that radios are picking up too much background noise and not enough voice. There's also comments about bad coverage in some areas (Orpington) and alert tones being far too loud.

I am still seeing a mixture of MPT and DMR now and some DMR site(s) have enabled encryption.

Currently, the old MPT control channels are still running and at the same power levels. I still see some traffic daytimes. However, a vast number of bus companies have moved over to the Tait/Hytera system.